/*******************************************************************************
 * Copyright 2009, 2010 Innovation Gate GmbH. All Rights Reserved.
 * 
 * This file is part of the OpenWGA server platform.
 * 
 * OpenWGA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * In addition, a special exception is granted by the copyright holders
 * of OpenWGA called "OpenWGA plugin exception". You should have received
 * a copy of this exception along with OpenWGA in file COPYING.
 * If not, see <http://www.openwga.com/gpl-plugin-exception>.
 * 
 * OpenWGA is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with OpenWGA in file COPYING.
 * If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/

package de.innovationgate.wga.modules.options;

import java.util.HashMap;
import java.util.Map;

import de.innovationgate.wga.config.WGAConfiguration;
import de.innovationgate.wga.modules.ModuleDefinition;

/**
 * An option reader that caches once read and converted values
 */
public class CachingOptionReader {
    
    private Map<String,Object> _cache = new HashMap<String, Object>();
    private WGAConfiguration _config;
   
    protected CachingOptionReader(WGAConfiguration config) {
        _config = config;
    }

    public Object readOptionValueOrDefault(Map<String,String> options, String optionName, ModuleDefinition modDef) throws OptionConversionException {
        
        
        String cacheKey = System.identityHashCode(options) + "//" + optionName;
        Object cachedValue = _cache.get(cacheKey);
        if (cachedValue != null) {
            return cachedValue;
        }
        
        OptionReader reader = OptionReader.create(options, modDef);
        Object value = reader.readOptionValueOrDefault(optionName);
        if (value != null) {
            _cache.put(cacheKey, value);
        }
        return value;
    }

}
